This work argues that congregational and local denominational schisms among Baptists, Methodists, and Presbyterians in the border state of Missouri before, during, and after the Civil War were central to the crisis of the Union, Civil War, and Reconstruction. Employing an array of approaches that examine these ecclesiastical fractures beyond the customary antebellum temporal scope of analysis, and as a local phenomenon, this study maintains that the schisms were interlinked religious, sociocultural, legal, and political developments rife with implications for the transformation of evangelicalism and the United States in that period and to the end of Reconstruction. The evangelical disruptions in Missouri were grounded in divergent moral and political understandings of slavery, abolitionism, secession, and disloyalty. Publicly articulated by factional litigation over church property and a combative evangelical print culture, the schisms were complicated by race, class, and gender dynamics that arrayed the contending interests of white middle-class women and men, rural churchgoers, and African American congregants. These ruptures forged antagonistic northern and southern evangelical worldviews that increased antebellum sectarian strife and violence, energized the notorious guerrilla conflict that gripped Missouri through the Civil War, and fueled postwar vigilantism between opponents and proponents of emancipation. As such, the schisms produced the intertwined religious, legal, and constitutional controversies that shaped pro- and antislavery evangelical contention before 1861, wartime Radical rule, and the rise and fall of Reconstruction.